When comparing Polar M400 vs Withings Go, the Slant community recommends Polar M400 for most people. In the question“What are the best fitness trackers?”Polar M400 is ranked 3rd while Withings Go is ranked 11th. The most important reason people chose Polar M400 is:

The "Sport Profile" feature allows you to customize what stats you want to see for each type of exercise. For example, you may want the GPS on for running but not for a circuit workout. These preset profiles save you from having to set up the device each time you exercise.

Pros

Pro

Gives you a lot of options for customizing different types of workouts

The "Sport Profile" feature allows you to customize what stats you want to see for each type of exercise. For example, you may want the GPS on for running but not for a circuit workout. These preset profiles save you from having to set up the device each time you exercise.

Pro

Gives you custom activity goals suitable for your level

The daily activity goal is a good way to find out how active you really are in your everyday life. Here you can choose your typical activity level from three options and see how active you need to be to reach your daily activity goal.

The time you need to complete your daily activity goal depends on the level you have chosen and the intensity of your activities. Age and gender also affect the intensity you need to reach your daily activity goal.

Pro

Detailed reports

Pro

Ability to add training notes

The app allows you to add additional notes to your workouts for better tracking.

Pro

Very easy to read the display in all lighting conditions

The Withings Go fitness tracker uses an E ink screen, the same as what you would find on an e-reader. Rather than being lit like a usual digital screen, it is much more similar to ink on paper. This makes it very easy to read even in very bright conditions or when in the water.

Pro

Water won't cause it any issues

The Withings Go is water-resistant up to 50m. Not only can it easily handle wet weather and sweat, but you can confidently wear it swimming or in the shower.

Pro

The display is very simple to use

The display is wonderfully simple so there is 0 time spent on fiddling with settings and figuring out how the display works.

Pressing on the display will switch between the time, and your activity progress.

Pro

Can go up to 8 months on a single battery

The Withings Go fitness tracker cannot be recharged, but can last up to 8 months on a single battery.

Cons

Con

Sleep tracking lacks detail and accuracy

If you are awake for an extended period of time in the middle of the night and then fall back asleep, the fitness tracker may not see the additional hours as part of your sleep.

Con

Unattractive and bulky design

The tracker is quite wide and hard to miss, it's not something that can blend in with what you're wearing outside of sport/exercise type settings.

Con

Short battery life when using the GPS

With the GPS turned on, battery life goes from around 24 days to 9 hours.

This is likely fine for people who will always have opportunities to charge it after their run. However for anyone hoping to use the GPS for longer activities, such as hiking, that may not be long enough to be useful.

Con

Very inaccurate sleep tracker

The Withings Go is not a good option for someone wanting accurate data on their sleep habits.

It often doesn't detect times you wake up at all, or sometimes registers them as "light sleep". Many users have reported the number of hours spent sleeping being consistently off by a couple hours or more.

Con

Known to underestimate step count

A common complaint is that the Withings Go fitness tracker will underestimate the steps taken. This is the opposite of many trackers which are often known for overestimating the step count.